1. Field of the Invention
The present invention relates to a headgear frame apparatus of a sewing machine for embroidering a headgear.
2. Description of the Related Art
As shown in FIG. 6, a conventional headgear frame apparatus 105 is provided with a cylindrical rotary drive frame 106 for turning a headgear 1 in front of a sewing machine frame in the circumferential direction of the circumferential portion 5 of the headgear 1, and a headgear frame 100 detachably attached to the rotary drive frame 106.
On the outer circumference of the rotary drive frame 106, there are disposed three holding rollers 107 which are equidistantly spaced in the circumferential direction for fixing the headgear frame 100. These holding rollers 107 are biased by (not-shown) springs to hold the outer circumference of the rotary drive frame 106.
A receiving frame 101 of the headgear frame 100 is provided with three engaging holes 108 corresponding to the individual holding rollers 107. When this headgear frame 100 is to be attached to the rotary drive frame 106, its receiving frame 101 is fitted and forced on the rotary drive frame 106. Then, the individual holding rollers 107 come into engagement with the engaging holes 108 so that the headgear frame 100 is fixed. When the headgear frame 100 is detached, on the other hand, it is forcibly pulled from the rotary drive frame 106. Then, the individual holding rollers 107 are disengaged from the engaging holes 108.
Here, in order to fixing the headgear frame 100 on the rotary drive frame 106 without any chatter, it is necessary to intensify the pushing forces of the holding rollers 107. Then, the headgear frame 100 has to be pushed or pulled by accordingly strong forces for bringing the holding rollers 107 into or out of engagement with the engaging holes 108 when the headgear frame 100 is to be attached or detached. This makes these attaching and detaching works difficult for the powerless worker.
When the headgear frame 100 is to be removed, on the other hand, the strong pulling force is required till the holding rollers 107 and the engaging holes 108 come out of engagement. After this disengagement, however, the receiving frame 101 of the headgear frame 100 is just fitted on the rotary drive frame 106 so that the headgear frame 100 can be easily removed by a weak force. If the headgear frame 100 is pulled extensively strongly, therefore, the holding rollers 107 and the engaging holes 108 are disengaged, but simultaneously with this, the headgear frame 100 may entirely come out from the rotary drive frame 106. This makes it difficult to moderate the force for pulling the headgear frame 100.
In order to ensure the attachment of the headgear frame 100, moreover, the engagement between the holding rollers 107 and the engaging holes 108 has to be visually confirmed, and this confirmation is troublesome.
Thus, it is not efficient to attach and detach the headgear frame 100 to and from the rotary drive frame 106 which is disposed on the sewing machine side.